Pax Americana is the Latin term for the idea that American power underwrites the post-1945 world order. If there’s a major international problem, the underlying assumption is that the United States needs to take the lead in resolving or containing it. Other countries may play a supporting role but the Americans need to do the bulk of the heavy lifting.

For Canadians, this is a sweet deal. We get to participate at whatever level we deem appropriate while reserving our right to criticize. So over the past half-century, we’ve refashioned our national self-image to that of benignly impartial peacekeepers. It distinguishes us from the Americans, which is always considered a plus.

Yes, we intellectually recognize that the peace sometimes needs to be made before it can be kept but we’d generally prefer to stay aloof from the messy part. We’re just a small country that’s chosen to have a very modest military capability. That’s who we are.

But what happens if the Americans decide that Pax Americana isn’t such a great idea? After all, most international flashpoints have limited direct impact on American interests.

Certainly, an acute perception of self-interest has always underpinned Pax Americana. But in the era of President Donald Trump, there are indications of a narrower, even transactional, view of such self-interest. Lots of commentators find this alarming.

And as a Canadian, it doesn’t thrill me. Although there are things I don’t like about post-1945 American foreign policy, the idea of their significantly withdrawing from the world isn’t a happy one. Because there are bad guys and bullies out there, a muscular cop – however imperfect – brings a degree of reassurance.

However, if I were an American, I might have a different perspective. The question I’d ask myself is whether Pax Americana is really worth the cost.

Korea, where the Americans led the 1950 to 1953 United Nations action, did indeed roll back the Soviet-approved North Korean invasion, thus providing the breathing space that ultimately facilitated the emergence of South Korea as a democratic and industrial powerhouse. But it cost the lives of 36,000 American soldiers and precipitated a long-term commitment that still consumes resources and creates substantial anxiety.

Skipping forward to today, my American incarnation would be vexed by the question of what to do with Russia. Oh, I’d have no difficulty understanding why Russian President Vladimir Putin might make Europeans nervous. Front-line states like Poland, Ukraine and the Baltics have particularly obvious reasons for angst.

But I’d also wonder why Russia isn’t primarily a European problem. The European Union’s population is several times larger than Russia’s and it’s also far richer. So if it’s necessary to deter or contain Putin, they should be perfectly capable of doing it. And if they’re not prepared to invest in the requisite muscle, why should the lead fall to the United States?

I’d also be concerned about endless wars where the rules of engagement prevent the kind of decisive victory that characterized the Second World War. Or, for that matter, the American Civil War.

Speaking of Afghanistan, former American diplomat Ryan Crocker has noted that “defeat has meaning only in the eyes of the defeated. The Taliban is not feeling defeated.”

Further illustrating his point, Crocker referred to his own father’s Second World War experience flying B-17s over Germany and reducing cities like Dresden to rubble: “That’s how you get people to feel defeated, and no sane person would argue for doing it again.”

In effect, Pax Americana gets you involved in conflicts where much of your nominal strength is an illusion. Either the nature of the conflict doesn’t lend itself to deploying that strength or the rules of engagement put tight fences around it.

According to a recent Washington Post story, U.S. officials in Afghanistan now track more than 700 benchmarks designed to capture progress. But in the words of one senior adviser, “Are these the metrics that put you on the trajectory to winning? How will you even know when you get there?”

Finally, let’s return to Crocker’s point concerning the Second World War air campaign. If that’s how you get people to feel defeated but no sane person would argue for doing it, then we’re effectively saying that a power like Nazi Germany couldn’t be beaten again.

Now there’s a sobering thought.

Troy Media columnist Pat Murphy casts a history buff’s eye at the goings-on in our world. Never cynical – well, perhaps just a little bit.